JAVA-14471 remove extra dependency, set start class, upgrade

spring-boot-modules/spring-boot-keycloak/pom.xml

@@ -18,10 +18,6 @@
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter</artifactId>
-        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
@@ -81,7 +77,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>jaxb2-maven-plugin</artifactId>
-                <version>2.3.1</version>
+                <version>2.5.0</version>
                 <executions>
                     <execution>
                         <id>xjc</id>
@@ -100,5 +96,9 @@
             </plugin>
         </plugins>
     </build>
+    
+     <properties>
+        <start-class>com.baeldung.keycloak.SpringBoot</start-class>
+    </properties>
 
 </project>